How Does Vidaza Work For Myelodysplastic Syndrome & Can It Cure MDS?

Vidaza which is the trade name of the drug azacitidine belongs to the drug group hypomethylating agents. It is an approved chemotherapy drug for:

• Myelodysplastic syndrome (MDS)
• Refractory anemia
• Refractory anemia with ring sideroblasts (if neutropenia and thrombocytopenia is present or transfusions are required)
• Refractory anemia with excess blast cells
• Refractory anemia with excess blast cells in transformation
• Acute myeloid leukemia (AML)
• Chronic myelomonocytic leukemia (CMML) ⁽¹⁾

Vidaza or azacitidine (5-azacytidine) is a pyrimidine (one of the bases in DNA and RNA) nucleoside analog of cytidine. It has an antineoplastic activity by two mechanisms:

Hypomethylation (modification of the DNA by the loss of the methyl group) of DNA (low doses)

Direct cytotoxicity on the abnormal cells there in the bone marrow by incorporating into the DNA and RNA which results in cellular death. (High doses). Vidaza is a ribonucleoside, so, it incorporates more into RNA than to DNA.

The cytotoxicity is imposed on the rapidly dividing cells which include cancer cells that are not responding to the normal cell growth mechanisms and the drug destroy these cells. Normally dividing cells are usually, insensitive to azacytidine therefore; the normal healthy hematopoetic cells can be preserved.

• Preparations – intravenous (IV) and subcutaneous (SC) preparations
• Absorption – Vidaza or azacitidine is absorbed rapidly with SC route and the bioavailability of SC azacitidine is about 89% when compared with the IV azacitidine. Peak plasma time is 30 minutes
• Metabolism – it is not clear if azacitidine is metabolized by the liver or not.
• Elimination – the t half-life is 4 hours mainly excreted by urine (50-85%), a minority through feces.

No, Vidaza or azacitidine does not cure myelodysplastic syndrome. The only potential cure for myelodysplastic syndrome is allogeneic stem cell transplantation but unfortunately, most patients diagnosed with myelodysplastic syndrome are elderly people with other comorbidities therefore, most of them are not candidates for transplantation. The introduction of Vidaza is a major advancement in the treatment of myelodysplastic syndrome for patients who are not suitable for transplantation, but it does not cure myelodysplastic syndrome. Vidaza reduces the symptoms, reduce the risk of AML and improves the overall quality of life; it is safe and effective for elderly patients as well. Studies have shown that many patients benefit and live longer with Vidaza than with conventional treatment. However, only about 50% of the patient’s response to the drug and from the people respondent most of them relapse in 2 years and the outcome after a relapse is very poor. ⁽¹⁾

The dosage depends on the condition and severity. Your doctor will choose the best route, dose, and frequency suitable for you. The response is not immediate; few cycles of Vidaza should be administered to see the response. It can be continued until patient tolerates and benefit from the drug.

There are many side effects, some of the common side effects are:

• Nausea
• Anemia
• Fever
• Thrombocytopenia
• Ecchymosis
• Petechiae
• Leukopenia
• Diarrhea
• Constipation
• Fatigue
• Injection site erythema
• Injection site pain

• Hypersensitivity/allergic reaction to azacitidine or mannitol
• Pregnancy/lactation
• Advanced malignant hepatic tumors

Females should not get pregnant while on the treatment as it can harm the baby.

Since, this drug is eliminated mainly by the renal tract, renal failure, and other renal disorders should be checked by doing a renal function test before the initiation of treatment. Then, it should be monitored throughout the treatment period as well. Especially in the elderly people dose should be adjusted accordingly.

Liver functions are also checked at the baseline then throughout the treatment period. ⁽¹⁾

Vidaza is the trade name of the drug azacitidine which belongs to the drug group hypomethylating agents. Vidaza or Azacitidine (5-azacytidine) is a pyrimidine nucleoside analog of cytidine. It has an antineoplastic action by hypomethylation of DNA when given in low doses and direct cytotoxicity on the abnormal cells present in the bone marrow by in cooperating into the DNA and RNA which results in cellular death with high does. The only potential cure for myelodysplastic syndrome is allogeneic stem cell transplantation and Vidaza does not cure myelodysplastic syndrome but it is an efficient and safe drug for myelodysplastic syndrome and its introduction is one of the major advancements in myelodysplastic syndrome treatment.

References:

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1936359/

Also Read:

• Myelodysplastic Syndromes Treatments: Chemotherapy, Immunotherapy, Bone Marrow Transplant
• Myelodysplastic Syndromes: Survival Rates, Prognosis, Recurrence, Remission, Lifestyle Changes, Prevention
• Coping with Myelodysplastic Syndromes & its Follow-Up Care
• How Do Myelodysplastic Syndrome Patients Die?
• Is Myelodysplastic Syndrome A Fatal Disease?
• Recovery Period For Myelodysplastic Syndrome
• What To Eat & Avoid When You Have A Myelodysplastic Syndrome?